Forever Knight
Eye See You
I do think after this Rider vs. Sentai movie they should take a breather on it and focus solely on the current Rider & Sentai team.
This is exactly how Kamen Rider was before the Heisei Decade :redface2::shakefist, now everyone has them at separate continuities.
I think more after the Kamen Rider/Super Sentai will be overkill. I hope they drop it for a few more years and focus on annual team-ups. When it's time for the anniversary again, that is when they should do them again.
It always seemed to me like they had an integrated universe too. In X Tachibana mentions the previous Riders when meeting Keisuke and even Destron too, in Amazon... well I don't remember that much so maybe he didn't. In Stronger, even though they don't mention them until their appearance in the end, when they do appear though, they're recognized as familiar faces right away and there's an explanation as to where they've been all this time. I think that's important because nowadays they don't even bother to do that.Rider's always been hot and cold with how it treats its continuity. The original show and V3 can be very easily viewed as a coherent continuity. In later shows, even when you had Tachibana there, the stories just ignored any part of continuity that didn't suit the show's goals. So Amazon has very few references to the other Riders, while in Skyrider they arguably end up eating the show.
Part of why I think this hot and cold attitude was allowed to develop is that Rider had a lot of very big hits that appeared to perform better by virtue of being clean slates: Black, Kuuga, Heisei's early glory days (sans Agito, which took a more old-fashioned approach). Ultraman's track record with "clean slate" shows is much rockier... there's not as many of them, and only a handful of them are among the franchise's biggest hits.
In X Tachibana mentions the previous Riders when meeting Keisuke and even Destron too, in Amazon... well I don't remember that much so maybe he didn't.
Once you hit X, I think the hot-and-cold approach starts to set in, where they're basically rebooting for the first half of the show and them remember that continuity exists when the crossovers start.